Photographic elements containing new dye-forming tris couplers

ABSTRACT

Dye-forming couplers provided by the invention are tris coupler compounds, each comprising three coupling moieties bonded to a phosphorous-containing tris linking group represented by ##STR1## has the structure (I): ##STR2## wherein each --R-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, or aryloxylene group. Dyes of the invention are the dyes that are formed by coupling reaction of an oxidized photographic color developing agent and the new tris couplers of the invention. Photographic elements of the invention each comprise a support having thereon a photographic silver halide emulsion layer and one or more of the new tris couplers of the invention.

FIELD OF THE INVENTION

This invention relates to new dye-forming couplers and new dyes formed therefrom and to photographic silver halide elements containing such new couplers. More particularly, the invention concerns new dye-forming tris couplers comprising three coupling moieties bonded to a phosphorous-containing linking group.

BACKGROUND

Color images are commonly obtained in the silver halide photographic art by reaction between the development product of a silver halide developing agent (e.g., oxidized aromatic primary amine developing agent) and a color forming compound commonly referred to as a coupler. The reaction between the coupler and oxidized developing agent results in coupling of the oxidized developing agent to the coupler at a reactive site on the coupler, known as the coupling position, and yields a dye. The subtractive process of color formation is ordinarily employed in color photographic elements, and the dyes produced by coupling are usually cyan, magenta, or yellow dyes which are formed in or adjacent to silver halide emulsion layers sensitive to red, green, or blue radiation, respectively.

Couplers well known for forming magenta dyes include, e.g., pyrazolones and bicyclic pyrazoloazoles, as described, for example, in U.S. Pat. Nos. 3,725,067; 3,810,761; 4,443,536; 4,540,654; and 4,621,046.

Well known couplers usually employed for forming cyan dyes include, e.g., substituted phenols and naphthols, as described, for example, in U.S. Pat. Nos. 2,367,531; 2,423,730; 2,474,293; 2,772,162; 2,895,826; 3,002,836; 3,034,892; 3,041,236; 3,998,642; 4,333,999; and 4,443,536.

Many couplers well known for forming yellow dyes contain an open-chain ketomethylene group in the coupling moleties. One class of such couplers comprises acylacetanilides, such as pivalylacetanilides and benzoylacetanilides, described, for example, in U.S. Pat. Nos. 2,407,210; 3,265,506; 3,408,194; 3,894,875; and 4,157,919.

However, such known couplers often have drawbacks.

One common drawback is the relatively high equivalent weight of many couplers. The term, "equivalent weight", as used herein is equal to the molecular weight of the coupler divided by the number of efficiently reactive coupling moieties in the coupler molecule. Each efficiently reactive coupling moiety is capable of reacting with oxidized developing agent to form a colored dye moiety. The higher the equivalent weight of the coupler is, the larger is the mass of coupler that must be included in a photographic element layer in order to be able to produce the desired amount of developed image dye optical density. The need for a larger mass of coupler in a layer results in a thicker layer, which inherently reduces the transparency and the optical sharpness of the layer. Thus, lower equivalent weight couplers allow for thinner, more transparent, optically sharper layers. Unfortunately, the overall mass of a coupler molecule must be relatively large in order to provide sufficient organic ballast to properly suspend the coupler molecules in droplets of high boiling organic liquid, referred to as coupler solvent, which are dispersed in the desired layer of the photographic element, and thereby anchor the coupler in the layer and prevent it from diffusing to adjacent layers or out of the element during processing with various aqueous processing liquids. Thus, the needs for lower equivalent weight and sufficient organic ballast are at apparent cross-purposes.

There is therefore a continuing need for new dye-forming couplers that can minimize the drawbacks described above, i.e., that have relatively low equivalent weight, while at the same time having relatively high molecular weight to provide sufficient organic ballast for proper incorporation and anchoring in photographic element layers. Of course, the couplers should also exhibit all the other characteristics desirable for good photographic performance.

SUMMARY OF THE INVENTION

The present invention meets the above-noted need by providing new dye-forming couplers, new dyes formed therefrom, and new photographic elements containing the new couplers.

The new dye-forming couplers provided by the invention are tris coupler compounds, each comprising three coupling moleties bonded to a phosphorous-containing tris linking group represented by ##STR3## has the structure (I): ##STR4## wherein each --R-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, or aryloxylene group.

The new dyes of the invention are the dyes that are formed by coupling reaction of an oxidized photographic color developing agent and the new tris couplers of the invention.

The photographic elements of the invention each comprise a support having thereon a photographic silver halide emulsion layer and one or more of the new tris couplers of the invention.

The couplers, dyes, and photographic elements of the invention provide a number of advantages.

Couplers of the invention have relatively low equivalent weight, because each coupler molecule contains three efficiently reactive coupling moleties bonded to a central linking group of structure (I). Thus the equivalent weight of the couplers of the invention is only one third of their molecular weight, and layers in photographic elements of the invention containing such couplers can be made thinner and thus more transparent and optically sharper.

Conversely, the three coupling moieties plus linking group in couplers of the invention result in the couplers' having relatively high molecular weights, which easily provides sufficient organic ballast to properly suspend the coupler molecules in coupler solvent and anchor them in layers of photographic elements of the invention.

Furthermore, it was unpredictable that inclusion of the phosphorous-containing linking group of structure (I) in the coupler molecules would still yield couplers having the other characteristics necessary or desirable for good photographic performance. The couplers of the invention have been unexpectedly found to have such characteristics. For example, the inventive couplers are compatible with common coupler solvents and are efficiently reactive with oxidized photographic color developing agents to form dye and, when incorporated in silver halide photographic elements, provide good photographic speed. The inventive dyes formed by the couplers afford high maximum density (Dmax) and contrast and good peak spectral absorptivity at desired wavelengths, and images formed by such dyes in photographic elements of the invention exhibit good thermal, hydrolyric, chemical, and light stabilities. The couplers and dyes of the invention do not adversely interact with other common components that may be included in photographic elements of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

While all the couplers of the invention contain the phosphorous-containing tris linking group of structure (I) above, in some embodiments the linking group contains additional moleties. For example, in some embodiments the tris linking group has the structure (II): ##STR5## wherein --R-- is as previously described.

Also, in some embodiments the tris linking group has the structure (III): ##STR6## wherein --R-- is as previously described, and each --L-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, aryloxylene or aryloxyalkylene group.

Each coupler molecule of the invention also contains three coupling moieties, each bonded to the tris linking group through a different one of each of the three free bonds shown in Structure (I), (II), or (III), above. The coupling moieties can be any of those coupling moieties useful for forming dye moleties by reaction with oxidized developing agent in silver halide photographic elements. The particular coupling moieties employed are chosen depending upon the hue and other characteristics desired to be imparted to any particular photographic element of the invention.

For example, when it is desired to provide magenta-dye-forming properties, the coupling moieties can be chosen from any of those known to be useful for that purpose, e.g., from pyrazolones and pyrazoloazoles, as described, for example, in U.S. Pat. Nos. 3,725,067; 3,810,761; 4,443,536; 4,540,654; and 4,621,046, the disclosures of which are hereby incorporated herein by reference.

When it is desired to provide cyan-dye-forming properties, the coupling moieties can be chosen from any of those known to be useful for that purpose, e.g., from substituted phenols and naphthols, as described, for example, in U.S. Pat. Nos. 2,367,531; 2,423,730; 2,474,293; 2,772,162; 2,895,826; 3,002,836; 3,034,892; 3,041,236; 3,998,642; 4,333,999; and 4,443,536, the disclosures of which are hereby incorporated herein by reference.

When it is desired to provide yellow-dye-forming properties, the coupling moieties can be chosen from any of those known to be useful for that purpose, e.g., from those containing an open-chain ketomethylene group, such as acylacetanilides, including, e.g., pivalylacetanilides and benzoylacetanilides, described, for example, in U.S. Pat. Nos. 2,407,210; 3,265,506; 3,408,194; 3,894,875; and 4,157,919, the disclosures of which are hereby incorporated herein by reference.

In some preferred embodiments of magenta-dye-forming couplers of the invention the coupling moieties in the coupler molecules have the structure (IV): ##STR7## wherein: each R¹ -- is independently H-- or a substituent;

each X-- is independently H-- or a coupling-off group; and

each of D, E, and Z is independently a substituted or unsubstituted methine group, ═N--, or --NH--, with the provisos that one of either the D-E or E-Z bonds is a double bond and the other a single bond, and one of D, E, and Z is a methine group bonded to the tris linking group through one of the three free bonds shown in Structure (I), (II), or (III), above.

In more preferred embodiments of magenta-dye-forming couplers of the invention the coupling moieties in the coupler molecules have the structure (V): ##STR8## wherein R¹ -- and X-- are as previously defined for Structure (IV), and the coupling moiety is bonded to the tris linking group through connection of the free bond shown in Structure (V) to one of the three free bonds shown in Structure (III).

In some preferred embodiments of cyan-dye-forming couplers of the invention the coupling moieties in the coupler molecules have either the structure (VI): ##STR9## or the structure (VII): ##STR10## wherein each R¹ --, R² --, R³ --, and R⁴ -- is independently H-- or a substituent; each X-- is independently H-- or a coupling-off group; the free bond shown in Structure (VI) is connected to one of the three free bonds shown in Structure (III); and the free bond shown in Structure (VII) is connected to one of the three free bonds shown in Structure (II).

In more preferred embodiments of Structure (VII), the coupling moieties in the coupler molecule have the structure (VIII): ##STR11## wherein R¹ --, R² --, R³ --, and R⁴ -- are as previously defined for Structure (VII), and the free bond shown in Structure (VIII) is connected to one of the three free bonds shown in the Structure (II) tris linking group.

In some preferred embodiments of yellow-dye-forming couplers of the invention the coupling moieties in the coupler molecules have either the structure (IX): ##STR12## or the structure (X): ##STR13## wherein: each R¹ -- is independently t-butyl or a substituted aryl group;

each Z-- is independently H--, halo, or a substituted or unsubstituted alkyl, aryl, alkoxy, or aryloxy group;

each X-- is independently H-- or a coupling-off group;

each M-- is independently H-- or a substitutent;

each R² -- is independently H-- or a substituent; the free bond shown in Structure (IX) is connected to one of the three free bonds shown in Structure (I); and the free bond shown in Structure (X) is connected to one of the three free bonds shown in Structure (I).

In more preferred embodiments of Structures (IX) and (X), the coupling moieties in the coupler molecule have the structures (XI) and (XII), respectively: ##STR14## wherein: R¹ --, Z--, X--, M--, and R² -- are as previously defined for Structures (IX) and (X); the free bond shown in Structure (XI) is connected to one of the three free bonds shown in Structure (I); and the free bond shown in Structure (XII) is connected to one of the three free bonds shown in Structure (I).

As used herein, the terms "substituent" and "substituted" are meant to denote a wide range of various groups which can be chosen, as is well known in the art, depending upon the effect or lack of effect desired on various characteristics of the couplers, e.g., solubility, diffusion resistance, dye hue, dye stability, etc. Such groups include, for example: halo, e.g., chloro, bromo or fluoro; nitro; hydroxyl; cyano; and carboxyl and its salts; and groups which may be further substituted, such as alkyl, including straight or branched chain alkyl, such as methyl, trifluoromethyl, ethyl, t-butyl, 3-(2,4-di-t-amylphenoxy) propyl, and tetradecyl; alkenyl, such as vinyl and 2-butenyl; alkoxy, such as methoxy, ethoxy, propoxy, butoxy, 2-methoxyethoxy, sec-butoxy, hexyloxy, 2-ethylhexyloxy, tetradecyloxy 2-(2,4-di-t-pentylphenoxy) ethoxy, and 3-dodecyloxyethoxy; aryl such as phenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, naphthyl; aryloxy, such as phenoxy, 2-methylphenoxy, alpha- or beta-naphthyloxy, and 4-tolyloxy; amido, such as acetamido, benzamido, butyramido, tetradecanamido, alpha-(2,4-di-t-pentyl-phenoxy) acetamido, alpha-(2,4-di-t-pentylphenoxy)butyramido, alpha-(3-pentadecylphenoxy)- hexanamido, alpha-(4-hydroxy-3-t-butylphenoxy)-tetradecanamido, 2-oxo-pyrrolidin-1-yl, 2-oxo-5-tetradecyl-pyrrolin-1-yl, N-methyltetradecanamido, N-succinimido, N-phthalimido, 2,5-dioxo-1-oxazolidinyl, 3-dodecyl-2, 5-dioxo-1-imidazolyl, and N-acetyl-N-dodecylamino, ethoxycarbonylamino, phenoxycarbonylamino, benzyloxycarbonylamino, hexadecyloxycarbonylamino, 2,4-di-t-butylphenoxycarbonylamino, phenylcarbonylamino, 2,5-(di-t-pentylphenyl) carbonylamino, p-dodecylphenylcarbonylamino, p-toluylcarbonylamino, N-methylureido, N,N-dimethylureido, N-methyl-N-dodecylureido, N-hexadecylureido, N, N-dioctadecylureido, N,N-dioctyl-N'-ethylureido, N-phenylureido, N,N-diphenylureido, N-phenyl-N-p-toluylureido, N-(m-hexadecylphenyl)ureido, N,N-(2,5-di-t-pentylphenyl) -N'-ethylureido; and t-butylcarbonamido; sulfonamido, such as methylsulfonamido, benzenesulfonamido, p-toluylsulfonamido, p-dodecylbenzenesulfonamido, p-toluylsulfonamido, p-dodecylbenzenesulfonamido, N-methyltetradecylsulfonamido, N,N-dipropylsulfamoylamino, and hexadecylsulfonamido; sulfamyl, such as N-methylsulfamyl, N-ethylsulfamyl, N,N-dipropylsulfamyl, N-hexadecylsulfamyl, N, N-dimethylsulfamyl, N-[3-(dodecyloxy)propyl]sulfamyl, N-[4-(2,4-di-t-pentylphenoxy)butyl]sulfamyl, N-methyl-N-tetradecylsulfamyl, and N-dodecylsulfamyl; carbamoyl, such as N-methylcarbamoyl, N,N-dibutylcarbamoyl, N-octadecylcarbamoyl, N-[4-(2,4-di-t-pentylphenoxy)butyl]carbamoyl, N-methyl-N-tetradecylcarbamoyl, and N,N-dioctylcarbamoyl; acyl, such as acetyl, (2,4-di-t-amylphenoxy)acetyl, phenoxycarbonyl, p-dodecyloxytphenoxycarbonyl methoxycarbonyl, butoxycarbonyl, tetradecyloxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl, 3-pentadecyloxycarbonyl, and dodecyloxycarbonyl; sulfonyl, such as methoxysulfonyl, octyloxysulfonyl, tetradecyloxysulfonyl, 2-ethylhexyloxysulfonyl, phenoxysulfonyl, 2,4-di-t-pentylphenoxysulfonyl, methylsulfonyl, octylsulfonyl, 2-ethylhexylsulfonyl, dodecylsulfonyl, hexadecylsulfonyl, phenylsulfonyl, 4-nonylphenylsulfonyl, and p-toluylsulfonyl; sulfonyloxy, such as dodecylsulfonyloxy, and hexadecylsulfonyloxy; sulfinyl, such as methylsulfinyl, octylsulfinyl, 2-ethylhexylsulfinyl, dodecylsulfinyl, hexadecylsulfinyl, phenylsulfinyl, 4-nonylphenylsulfinyl, and p-toluylsulfinyl; thio, such as ethylthio, octylthio, benzylthio, tetradecylthio, 2-(2,4-di-t-pentylphenoxy)ethylthio, phenylthio, 2-butoxy-5-t-octylphenylthio, and p-tolylthio; acyloxy, such as acetyloxy, benzoyloxy, octadecanoyloxy, p-dodecylamidobenzoyloxy, N-phenylcarbamoyloxy, N-ethylcarbamoyloxy, and cyclohexylcarbonyloxy; amino, such as phenylanilino, 2-chloroanilino, diethylamino, dodecylamino; imino, such as 1 (N-phenylimido) ethyl, N-succinimido or 3-benzylhydantoinyl; azo, such as phenylazo and naphthylazo; a heterocyclic group, heterocyclic oxy group or a heterocyclic thio group, each of which may be substituted and which contain a 3 to 7 menmbered heterocyclic ring composed of carbon atoms and at least one hetero atom selected from the group consisting of oxygen, nitrogen and sulfur, such as 2-furyl, 2-thienyl, 2-benzimidazolyloxy or 2-benzothiazolyl; quaternary ammonium, such as triethylammonium; and siloxy, such as trimethylsiloxy.

The particular substituents used may be selected to attain the desired photographic properties for a specific application and can include, for example, hydrophobic groups, solubilizing groups, blocking groups, etc. Generally, the above groups and substituents thereof may typically include those having 1 to 42 carbon atoms and typically less than 30 carbon atoms, but greater numbers are possible depending on the particular substituents selected. Moreover, as indicated, the substituents may themselves be suitably substituted with any of the above groups.

The term "alkyl" or "alkylene" standing alone herein or as part of another term is meant to denote C₁ -C₂₀ alkyl or alkylene.

The term "aryl" or "arylene" standing alone herein or as part of another term is meant to denote C₆ -C₁₂ aryl or arylene.

Suitable "coupling-off groups" such as represented by "X" at the coupling position in the structures herein are known to those skilled in the art. Such groups can determine the equivalency of the coupler, can modify the reactivity of the coupler, or can advantageously affect the layer in which the coupler is coated or other layers in the element by performing, after release from the coupler, such functions as development inhibition, development acceleration, bleach inhibition, bleach acceleration, color correction, and the like. Representative classes of coupling-off groups include halo, particularly chloro, bromo, or fluoro; alkoxy; aryloxy; heterocyclyloxy; heterocyclic, such as hydantoin and pyrazolyl groups; sulfonyloxy; acyloxy; amido; imido; acyl; heterocyclylimido; thiocyano; alkylthio; arylthio; heterocyclylthio; sulfonamido; phosphonyloxy; and arylazo. They are described, for example, in U.S. Pat. Nos. 2,355,169; 3,227,551; 3,432,521; 3,476,563; 3,617,291; 3,880,661; 4,052,212 and 4,134,766; the disclosures of which are hereby incorporated herein by reference.

Examples of specific coupling-off groups are Cl, F, Br, --SCN, OCH₃, --OC₆ H₅, --OCH₂ C(═O)NHCH₂ CH₂ OH, --OCH₂ C(═O)NHCH₂ CH₂ OCH₃, --OCH₂ C(═O)NHCH₂ CH₂ OC(═O)OCH₃, --NHSO₂ CH₃, --OC(═O)C₆ H₅, --NHC(═O)C₆ H₅, OSO₂ CH₃, --P(═O) (OC₂ H₅)₂, --S(CH₂)₂ CO₂ H, ##STR15##

In particularly preferred embodiments of magenta-dye-forming couplers of the invention containing three coupling moieties of Structure (IV) above, bonded to a tris linking group of Structure (III) above: each --R-- is independently phenylene or phenoxylene; each --L-- is independently propylene or phenoxytrimethylene; each R¹ -- is independently substituted or unsubstituted alkyl, with particularly preferred specific examples being methyl, t-butyl, or ##STR16## and each X-- is independently halo or a substituted or unsubstituted aryloxy, arythio, or nitrogen-containing heterocyclic group, with particularly preferred specific examples being chloro, 1-pyrazolyl, phenoxy, or phenylthio.

In particularly preferred embodiments of cyan-dye-forming couplers of the invention containing three coupling moieties of Structure (VI) or (VII) above, bonded to a tris linking group of Structure (III) or (II) above, respectively: each --R-- is independently phenylene or phenoxylene; each --L-- is independently a substituted or unsubstituted arylene or aryloxyalkylene group, with particularly preferred specific examples being tetrafluorophenylene, phenoxyrpropylidene, or phenoxyamylidene; each R¹ --, R² --, R³ --, and R⁴ -- is independently H--, halo, or substituted or unsubstituted alkyl, acylamino, or ureido, with particularly preferred specific examples being H--, chloro, methyl, ethyl, ##STR17## and each X-- is independently H-- or halo, with particularly preferred specific examples being H-- or chloro.

In particularly preferred embodiments of yellow-dye-forming couplers of the invention containing three coupling moieties of Structure (IX) or (X) above, bonded to a tris linking group of Structure (I) above: each --R-- is phenoxylene; each R¹ -- is t-butyl; each Z-- is independently ##STR18## each X-- is independently halo or a substituted or unsubstituted aryloxy or nitrogen-containing heterocyclic group, with particularly preferred specific examples being: ##STR19## each M-- is independently a substituted or unsubstituted sulfonamido, sulfamyl, alkoxycarbonyl, or acylamino group, with particularly preferred specific examples being ##STR20## and each R² -- is H--.

Some specific examples of magenta-dye-forming couplers of the invention are illustrated in Table I, showing the tris linking group of Structure (III) and the three couplers moieties of Structure (V), which together comprise each coupler molecule.

    TABLE I       Coupler Tris Linking Group Coupling Moieties           M-1       ##STR21##       ##STR22##       M-2      ##STR23##       ##STR24##       M-3      ##STR25##       ##STR26##       M-4      ##STR27##       ##STR28##       M-5      ##STR29##       ##STR30##       M-6      ##STR31##       ##STR32##       M-7      ##STR33##       ##STR34##       M-8      ##STR35##       ##STR36##       M-9      ##STR37##       ##STR38##       M-10      ##STR39##       ##STR40##       M-11      ##STR41##       ##STR42##

Some specific examples of cyan-dye-forming couplers of the invention are illustrated in Table II, showing the tris linking group of Structure (III) or (II) and the three coupling moieties of Structure (VI) or (VII), respectively, which together comprise each coupler molecule.

    TABLE II       Coupler Tris Linking Group Coupling Moieties           CY-1       ##STR43##       ##STR44##       CY-2      ##STR45##       ##STR46##       CY-3      ##STR47##       ##STR48##       CY-4      ##STR49##       ##STR50##       CY-5      ##STR51##       ##STR52##       CY-6      ##STR53##       ##STR54##       CY-7      ##STR55##       ##STR56##       CY-8      ##STR57##       ##STR58##       CY-9      ##STR59##       ##STR60##       CY-10      ##STR61##       ##STR62##

Some specific examples of yellow-dye-forming couplers of the invention are illustrated in Table III, showing the tris linking group of Structure (I) and the three coupling moieties of Structure (XI) or (XII), which together comprise each coupler molecule.

                                      TABLE III                                    __________________________________________________________________________     Cou-                                                                           pler                                                                              Tris Linking Group      Coupling Moieties                                   __________________________________________________________________________     Y-1                                                                                ##STR63##                                                                                              ##STR64##                                          Y-2                                                                                ##STR65##                                                                                              ##STR66##                                          Y-3                                                                                ##STR67##                                                                                              ##STR68##                                          Y-4                                                                                ##STR69##                                                                                              ##STR70##                                          Y-5                                                                                ##STR71##                                                                                              ##STR72##                                          Y-6                                                                                ##STR73##                                                                                              ##STR74##                                          Y-7                                                                                ##STR75##                                                                                              ##STR76##                                          Y-8                                                                                ##STR77##                                                                                              ##STR78##                                          Y-9                                                                                ##STR79##                                                                                              ##STR80##                                          Y-10                                                                               ##STR81##                                                                                              ##STR82##                                          Y-11                                                                               ##STR83##                                                                                              ##STR84##                                          Y-12                                                                               ##STR85##                                                                                              ##STR86##                                          Y-13                                                                               ##STR87##                                                                                              ##STR88##                                                                      ##STR89##                                          Y-14                                                                               ##STR90##                                                                                              ##STR91##                                          Y-15                                                                               ##STR92##                                                                                              ##STR93##                                          Y-16                                                                               ##STR94##                                                                                              ##STR95##                                          Y-17                                                                               ##STR96##                                                                                              ##STR97##                                          __________________________________________________________________________

Couplers of the invention can be readily prepared by known general condensation reactions starting with appropriate known derivatives of the coupling moieties and linking group. Some convenient general schemes are as follows, wherein --L-- and --R-- are as described in regard to linking group Structures (I), (II), and (III) above. ##STR98##

Some working examples of specific preparations of specific couplers of the invention are as follows:

PREPARATION EXAMPLE A: COUPLER M-4 OF TABLE I ##STR99##

To a stirred solution of 5.11 g (0.012 mole) of (1) in 25 mL of pyridine at room temperature was added 2.49 g (0.004 mol) of chlorosulfonylphenyl phosphate (2). After being stirred under nitrogen for 13 h, the reaction mixture was slowly poured into a mixture of ice and water containing 30 mL of concentrated hydrochloric acid. Filtration of the mixture afforded 7 g of crude product (M-4). Flash chromotography (silica gel, elution with gradient of 20-50% AcOEt/ligroin) yielded 4.30 g (60%) of tris coupler (M-4) as a white solid. Physical, combustion analysis and spectroscopic data are consistent with the assigned structure.

PREPARATION EXAMPLE B: COUPLER Y-1 OF TABLE III ##STR100##

To a stirred solution of 18.2 g (0.03 mole) of (3) in 150 mL of pyridine was added 6.21 g (0.01 mol) of (4). The reaction mixture was stirred at room temperature for 3 hours, then poured into ice-water. The resulting solid was collected under suction, washed with water, and dried in vacuo. Flash chromatography (silica gel, AcOEt) afforded 14 g (62%) of desired product (Y-1) as a white solid. Physical and spectroscopic data are consistent with the assigned structure. Anal. Calc'd for C₁₁₄ H₁₀₃ Cl₃ N₆ O₈ PS₆ :C, 58.67; H, 4.41; P, 1.33. Found: C, 58,91; H, 4.20; P, 1.35.

PREPARATION EXAMPLE C: COUPLER Y-2 OF TABLE III ##STR101##

To a solution of 24.2 g (0.03 mol) of (5) in 150 mL of dried tetrahydrofuran (THF) was added with vigorous stirring 1.2 g (0.03 mol) of sodium hydride (6) followed by the slow addition of 1.2 (0.01 mol) of phosphorus oxychloride (7) dissolved in 50 mL of dried THF. The reaction mixture was stirred at room temperature for 3 hours then poured into ice-water containing 5 mL of concentrated hydrochloric acid. The gummy solid was separated, triturated first with methanol and then with ligroine. Separation of the resulting material by filtration under suction afforded 18 g (73.2%) Of (Y-2) as a white solid. Thin layer chromatography (CH2C12/AcOEt: 5/1) indicated one spot material. Physical and spectroscopic data are consistent with the assigned structure. Anal. Calc'd for C₁₂₃ H₁₆₈ C₁₃ N₆ O₂₅ S₆ P: C, 60.05; H, 6.88; N, 3.42; P, 1.26. Found: C, 59.98; H, 6.85; N, 3.43; P, 1.29.

Dyes in accordance with the invention are those formed by well-known coupling reaction of an oxidized photographic color developing agent with a coupler, in this case a coupler in accordance with the invention.

The photographic elements of the invention each comprise a support having thereon a photographic silver halide emulsion layer and one or more of the new tris couplers of the invention. Such elements can contain any of the layers and components known in the photographic art, with at least one of the couplers therein being a coupler of this invention.

Couplers of the invention can be used in any of the ways and in any of the combinations in which couplers are used in the photographic art. Many such ways and combinations are well known to those in the photographic art. Typically, the coupler is incorporated in a silver halide emulsion and the emulsion is coated on a support to form a photographic element of the invention. Alternatively, the coupler can be incorporated in an element of the invention at a location adjacent to the silver halide emulsion where, during development, the coupler will be in reactive association with development products such as oxidized color developing agent. Thus, as used herein, the term "associated" signifies that the coupler is in the silver halide emulsion layer or in an adjacent location where, during processing, the coupler is capable of reacting with silver halide development products.

The photographic elements of the invention can be single color elements or multicolor elements. Multicolor elements contain dye-image-forming units sensitive to each of the three primary regions of the spectrum. Each unit can comprise a single emulsion layer or multiple emulsion layers sensitive to a given region of the spectrum. The layers of the element, including the layers of the image-forming units, can be arranged in various orders as known in the art. In an alternative format, the emulsions sensitive to each of the three primary regions of the spectrum can be disposed as a single segmented layer.

A typical multicolor photographic element of the invention comprises a support bearing a cyan-dye-image-forming unit comprising at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan-dye-forming coupler, a magenta-dye-image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta-dye-forming coupler, and a yellow-dye-image-forming unit comprising at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow-dye-forming coupler, at least one of the couplers in the element being a coupler of this invention. The element can contain additional layers, such as filter layers, interlayers, overcoat layers, subbing layers, and the like.

If desired, the photographic element can be used in conjunction with an applied magnetic layer as described in Research Disclosure, November 1992, Item 34390 published by Kenneth Mason Publications, Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire P010 7DQ, ENGLAND.

In the following discussion of some suitable materials for use in the emulsions and elements of this invention, reference will be made to Research Disclosure, Issue Number 908, December 1989, Item 308119, pages 993-1015, available as described above, which will be identified hereafter by the term "Research Disclosure." The contents of the Research Disclosure, including the patents and publications referenced therein, are incorporated herein by reference, and the Sections hereafter referred to are Sections of the Research Disclosure.

The silver halide emulsions employed in the elements of this invention can be either negative-working or positive-working. Some suitable emulsions and their preparation as well as methods of chemical and spectral sensitization are described in Sections I through IV. Color materials and development modifiers are described in Section IX, and various additives such as brighteners, antifoggants, stabilizers, light absorbing and scattering materials, hardeners, coating aids, plasticizers, lubricants and matting agents are described, for example, in Sections V, VI, VIII, X, XI, XII, and XVI. Manufacturing methods are described in Sections XIV and XV, other layers and supports in Sections XIII and XVII, processing methods and agents in Sections XIX and XX, and exposure alternatives in Section XVIII.

Preferred supports are paper, cellulose acetate, and poly(ethylene terephthalate).

Photographic elements can be exposed to actinic radiation, usually in the visible region of the spectrum, to form a latent image and then processed to form a visible dye image. Processing to form a visible dye image includes the step of contacting the element with a color developing agent to reduce developable silver halide and oxidize the color developing agent. Oxidized color developing agent in turn reacts with the coupler to yield a dye of the invention.

Preferred color developing agents are p-phenylenediamines. Especially preferred are:

4-amino N,N-diethylaniline hydrochloride,

4-amino-3-methyl-N,N-diethylaniline hydrochloride

4-amino-3-methyl-N-ethyl-N-(b-(methanesulfonamido)ethyl)aniline sesquisulfate hydrate,

4-amino-3-methyl-N-ethyl-N-(b-hydroxyethyl)aniline sulfate,

4-amino-3-b-(methanesulfonamido)ethyl-N,N-diethylaniline hydrochloride, and

4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene sulfonic acid.

With negative working silver halide this processing step leads to a negative image. To obtain a positive (or reversal) image, this step can be preceded by development with a non-chromogenic developing agent to develop exposed silver halide, but not form dye, and then uniformly fogging the element to render the unexposed silver halide developable. Alternatively, a direct positive emulsion can be employed to obtain a positive image.

Development is followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver and silver halide, washing and drying.

The following examples are presented to further illustrate some specific photographic elements of the invention containing couplers of the invention.

Comparative examples are also provided containing couplers outside the scope of the present invention. Comparative couplers employed are as follows: ##STR102##

EXAMPLES 1-15 AND COMPARATIVE EXAMPLES A-C Preparation of Photographic Elements

Dispersions of the couplers were prepared in the following manner: The quantities of each component are found in Table IV. In one vessel the coupler, stabilizer (2,2',3,3'-tetrahydro-3,3,3',3'-tetramethyl-5, 5', 6, 6'-tetrapropoxy-1, 1'-spirobi[1H-indene}) in the case of magenta-dye-forming couplers or stabilizer [2,2'-methylenebis(3-t-butyl-5-methylphenol)monoacetate] in the case of yellow-dye-forming couplers, coupler solvent (diethyl dodecanamide) in the case of magenta-dye-forming couplers or solvent (dibutyl phthalate) in the case of yellow-dye-forming couplers, and ethyl acetate were combined and warmed to dissolve. In a second vessel, gelatin, Alkanol XC™ (surfactant and Trademark of E. I. DuPont Co., USA) and water were combined and warmed to about 40° C. The two mixtures were mixed together and passed three times through a Gaulin colloid mill. The ethyl acetate was removed by evaporation and water was added to restore the original weight after milling.

                                      TABLE IV                                     __________________________________________________________________________                          Grams                                                                               Grams                                                                               Grams                                                                               Grams                                      Dispersion                                                                           Coupler                                                                             Grams                                                                               Grams                                                                               Coupler                                                                             Ethyl                                                                               12.5%                                                                               Alkanol                                                                              Grams                                Number                                                                               Number                                                                              Coupler                                                                             Stabilizer                                                                          Solvent                                                                             Acetate                                                                             Gelatin                                                                             XC (10%)                                                                             Water                                __________________________________________________________________________     1     Y-1  1.622                                                                               0.714                                                                               0.909                                                                               4.867                                                                               19.20                                                                               2.40  10.29                                2     Y-2  1.725                                                                               0.700                                                                               0.956                                                                               5.117                                                                               19.20                                                                               2.40  9.87                                 A     C-1  1.891                                                                               0.834                                                                               1.058                                                                               5.672                                                                               19.20                                                                               2.40  8.95                                 3     M-1  0.643                                                                               0.322                                                                               0.965                                                                               1.930                                                                               19.20                                                                               2.40  14.54                                4     M-2  0.743                                                                               0.372                                                                               1.115                                                                               2.230                                                                               19.20                                                                               2.40  13.94                                5     M-4  0.764                                                                               0.382                                                                               1.146                                                                               2.292                                                                               19.20                                                                               2.40  13.82                                B     C-2  0.733                                                                               0.366                                                                               1.098                                                                               2.198                                                                               19.20                                                                               2.40  14.00                                __________________________________________________________________________

Dispersion C was composed of comparison coupler C-3 (8.73% by weight), 3,4-dihydro-2,2,-dimethyl-4-(1-methylethyl-7-octyl-2H-benzopyran-6-ol) (3.714%), 2,5-di-sec-dodecylhydroquinone (0.873%), dibutyl phthalate (4.454%), and gelatin (8.69%).

The photographic elements were prepared by coating the following layers in the order listed on a resin-coated paper support:

    ______________________________________                                         1st Layer     3.23 g/m.sup.2                                                   Gelatin                                                                        2nd Layer                                                                      Gelatin       1.61 g/m.sup.2                                                   Coupler Dispersion                                                                           4.3 × 10-.sup.4 mole coupling moieties/m.sup.2 in                        the                                                                            case of magenta-dye-forming couplers                                           (Table VII)                                                                    7.0 × 10-.sup.4 mole coupling moieties/m.sup.2 in                        the case of yellow-dye-forming couplers                                        (Table V)                                                        AgCl emulsion 0.24 g Ag/m.sup.2 and blue-sensitized in the                                   case of yellow-dye-forming couplers                                            (Table V)                                                                      or                                                                             0.17 g Ag/m.sup.2 and green-sensitized in the                                  case of magenta-dye-forming couplers                                           (Table VII)                                                      3rd Layer                                                                      Gelatin       1.33 g/m.sup.2                                                   2-(2H-benzotriazol-2-yl)-                                                                    0.73 g/m.sup.2                                                   4,6-bis(1,1-dimethyl-                                                          propyl)phenol                                                                  Tinuvin 326 ™                                                                             0.13 g/m.sup.2                                                   (Ciba-Geigy)                                                                   4th Layer                                                                      Gelatin       1.40 g/m.sup.2                                                   Bis(vinylsulfonylmethyl)                                                                     0.14 g/m.sup.2                                                   ether                                                                          ______________________________________                                    

Exposing and Processing of Photographic Elements

The photographic elements were given stepwise exposures (to green light in the case of magenta-dye-forming couplers or to blue light in the case of yellow-dye-forming couplers) and processed as follows at 35° C.

Developer: 45 seconds

Bleach-Fix: 45 seconds

Wash (running water): 90 seconds

The developer and bleach-fix were of the following compositions:

    ______________________________________                                         Developer                                                                      Water                   700.00  mL                                             Triethanolamine         12.41   g                                              Blankophor REU ™ (Mobay Corp.)                                                                      2.30    g                                              Lithium polystyrene sulfonate (30%)                                                                    0.30    g                                              N,N-Diethylhydroxylamine (85%)                                                                         5.40    g                                              Lithium sulfate         2.70    g                                              N-{2-[4-amino-3-        5.00    g                                              methylphenyl)ethylamino]ethyl}-                                                methanesulfonamide, sesquisulfate                                              1-Hydroxyethyl-1,1-diphosphonic                                                                        0.81    g                                              acid (60%)                                                                     Potassium carbonate, anhydrous                                                                         21.16   g                                              Potassium chloride      1.60    g                                              Potassium bromide       7.00    g                                              Water to make           1.00    L                                              pH at 26.7° C. adjusted to 6.7                                          Bleach-Fix                                                                     Water                   700.00  mL                                             Solution of Ammonium thiosulfate                                                                       127.40  g                                              (56.4%) plus Ammonium sulfite (4%)                                             Sodium metabisulfite    10.00   g                                              Acetic acid (glacial)   10.20   g                                              Solution of Ammonium ferric                                                                            110.40  g                                              ethylene diaminetetraacetate (44%)                                             + Ethylenediamine tetraacetic acid                                             (3.5%)                                                                         Water to make           1.00    L                                              pH @ 26.7° C. adjusted to 6.7                                           ______________________________________                                    

Photographic Tests

In the elements containing yellow-dye-forming couplers, yellow dyes were formed upon processing. The following photographic characteristics were determined: D-max (the maximum density to blue light), D-min (the minimum density to blue light), contrast, relative photographic speed, and Lambda-max (the wavelength of peak absorption at a density of 1.0). These values for each example are tabulated in Table V.

                                      TABLE V                                      __________________________________________________________________________     Example                          Lambda-                                       Number                                                                              Dispersion                                                                           Coupler                                                                             D-max                                                                              D-min                                                                              Contrast                                                                            Speed                                                                              max                                           __________________________________________________________________________     1    1     Y-1  2.06                                                                               0.08                                                                               2.33 192 449                                           2    2     Y-2  2.03                                                                               0.07                                                                               2.27 188 447                                           Comp. A                                                                             A     C-1  1.49                                                                               0.06                                                                               1.60 176 445                                           __________________________________________________________________________

The equivalent weight of the coupler, which is important in determining the amount of coupler that must be coated, is equal to the molecular weight divided by the number of coupling moleties in the molecule. The equivalent weight advantage of the couplers of the invention is illustrated in Table VI.

                  TABLE VI                                                         ______________________________________                                         Coupler Number                                                                             Molecular Weight                                                                            Equivalent Weight                                     ______________________________________                                         Y-1         2334         778                                                   Y-2         2460         820                                                   C-1          909         909                                                   ______________________________________                                    

The data in the Tables V and VI confirm that the couplers of the present invention provide higher coupling efficiency (Dmax, contrast and speed) than the comparative example. Also, the couplers of this invention have lower equivalent weight than the comparative coupler, thus, providing a reduction of chemical load in the coating, resulting in a thinner coating that improves transparency and optical sharpness.

In the elements containing magenta-dye-forming couplers, magenta dyes were formed upon processing. The following photographic characteristics were determined: D-max (the maximum density to green light); D-min (the minimum density to green light); Lambda-max (the wavelength of peak absorption at a density of 1.0); and Bandwidth (the width of the absorption spectrum in nanometers at half the peak density). These values for each example are tabulated in Table VII.

                  TABLE VII                                                        ______________________________________                                         Example                                                                               Disper-                      Lambda-                                                                               Band-                               Number sion    Coupler  D-max D-min max    width                               ______________________________________                                         3      3       M-1      2.59  0.07  548    96                                  4      4       M-2      2.48  0.09  549    95                                  5      5       M-4      2.48  0.09  548    94                                  Comp. B                                                                               B       C-2      2.39  0.10  543    105                                 Comp. C                                                                               C       C-3      2.51  0.09  540    106                                 ______________________________________                                    

The equivalent weight advantage of the couplers of the invention is illustrated in Table VIII.

                  TABLE VIII                                                       ______________________________________                                         Coupler Number                                                                             Molecular Weight                                                                            Equivalent Weight                                     ______________________________________                                         M-1         1508         503                                                   M-3         1556         519                                                   C-2          572         572                                                   C-3          779         779                                                   ______________________________________                                    

The data from Tables VII and VIII show that the tris-magenta couplers of this invention coated at levels proportional to their equivalent weights provide dyes with narrower bandwidths than those obtained from the comparison examples.

The lower equivalent weights of the couplers of the present invention allow a reduction in coating load, resulting in thinner coating for improving transparency and optical sharpness of the layer.

The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it should be appreciated that variations and modifications can be effected within the spirit and scope of the invention. 

What is claimed is:
 1. A photographic element comprising a support having thereon a photographic silver halide emulsion layer and a dye-forming tris coupler comprising three coupling moieties bonded to a phosphorous-containing tris linking group represented by ##STR103## has the structure: ##STR104## wherein each --R-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, or aryloxylene group.
 2. The photographic element of claim 1, wherein ##STR105## is bonded to the three coupling moieties such ##STR106## is a coupling-off group for the coupling moieties.
 3. The photographic element of claim 1, wherein ##STR107## is bonded to the three coupling moieties such ##STR108## is not a coupling-off group for the coupling moieties.
 4. The photographic element of claim 1, wherein ##STR109## has the structure: ##STR110## wherein --R-- is as defined in claim
 1. 5. The photographic element of claim 1, wherein ##STR111## has the structure: ##STR112## wherein --R-- is as defined in claim 1, and each --L-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, aryloxylene or aryloxyalkylene group.
 6. The photographic element of claim 1, wherein each --R-- is independently phenylene or phenoxylene.
 7. The photographic element of claim 5, wherein each --L-- is independently propylene or phenoxytrimethylene. 